Malicious PDF — malware analysis report

Static analysis result for SHA-256 83fb597771cf45b2…

MALICIOUS

PDF

84.0 KB Created: 2021-09-05 08:08:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 277ccdd33ef04ab5c4e1775ba2696f1c SHA-1: 13fd2c4be9e0759f5ab454b390ecbcb81603c875 SHA-256: 83fb597771cf45b282cd6420324b40589084d4ded7ff55d8122d57ed96a8fb0e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous URLs pointing to other PDF files, indicating a likely phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The presence of multiple links to potentially compromised CMS upload directories further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://elyriacatholic1970.com/clients/7/79/79c6984f8945646ae1b55d50a6b4dbab/File/kowob.pdf In PDF document text
    • http://homeopathyhongkong.org/files/mepumadutafawisurizalemak.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/62633906561.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/585de9545b75b3fb07da1646c23607c8/jupemewajisufavilowufu.pdfIn PDF document text
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/af11876e00d8aa70197f1feaa0fa5c4f/29125960751.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607884efb9d9d---96238065089.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/8ad79c17e13d6c9587446b90c91e92e3/wuvusowinid.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210614_4F4D0000EF433765.pdfIn PDF document text
    • http://euro520.net/userfiles/file/1624160043346997016.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/mekipirubibuwemoleral.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/diwumivigopo.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/21298b8e4160aecf62480c7611422ef6/tudajibefetona.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/rowetagozazis.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/161129504adb4e---wujome.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ed3e0a834---35815809203.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/06fb54e8c24fcac9df13ee7bfbf7b2ce/63078718457.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/4h7bftcqpjajff0mkammln4eo0/depenis.pdfIn PDF document text
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/3vf14frdsg5h1adsd9bfaierjl/lukodugos.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160be7d9116ade---mifedexopavizezul.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607d28f3629b2---2423862806.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/94089745759.pdfIn PDF document text
    • http://ned.ru/uploads/files/memofalufosiposerebovov.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/53af185951b98e12e50e8ccdf1fa3313/jegimujajonabalabopano.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/rubikuxirujivaliwaze.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160afc5d118b13---tagofo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=ecological+footprint+worksheetPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B3 10920 bytes
SHA-256: 108c25d14e35879e30fce8460d494a6052222becf5353d3bfc2e13e712616838
font_01_sfnt_off0000fc0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001141d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1141D 18052 bytes
SHA-256: 4643534135dc6298871870167ff66046bc2cd442a3b9287878b9c878702153da